Block #182,692

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 9/27/2013, 12:21:19 PM · Difficulty 9.8575 · 6,616,845 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
46626b1d7e1a7cb6342bc4467c9ffef479add79b2387ba26a52aa40942836d49

Height

#182,692

Difficulty

9.857456

Transactions

12

Size

3.44 KB

Version

2

Bits

09db823f

Nonce

155,395

Timestamp

9/27/2013, 12:21:19 PM

Confirmations

6,616,845

Merkle Root

9abb4c0e46c2dbbc683f19c2db993a67c6eb061a6b6fbe3fc3d9ed6fb1578618
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

7.097 × 10⁹³(94-digit number)
70976078198735674814…41590221862817911039
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
7.097 × 10⁹³(94-digit number)
70976078198735674814…41590221862817911039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.419 × 10⁹⁴(95-digit number)
14195215639747134962…83180443725635822079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.839 × 10⁹⁴(95-digit number)
28390431279494269925…66360887451271644159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.678 × 10⁹⁴(95-digit number)
56780862558988539851…32721774902543288319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.135 × 10⁹⁵(96-digit number)
11356172511797707970…65443549805086576639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.271 × 10⁹⁵(96-digit number)
22712345023595415940…30887099610173153279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.542 × 10⁹⁵(96-digit number)
45424690047190831881…61774199220346306559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.084 × 10⁹⁵(96-digit number)
90849380094381663762…23548398440692613119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.816 × 10⁹⁶(97-digit number)
18169876018876332752…47096796881385226239
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

★☆☆☆☆
Rarity
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,640,347 XPM·at block #6,799,536 · updates every 60s
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